CONCORD — On June 18, Hans Florine turned 50 years old. To celebrate, the world-class climber and Lafayette resident took a solo hike.

He shimmied up the Triple Direct route, a 2,950-foot climb up the very vertical face of El Capitan in Yosemite Valley. On July 13, a day when temperatures peaked at 106 degrees and even bugs baked on the rocky cliff, Florine topped off with a first-ever, in-one-day world record of 17 hours, 29 minutes.

At a free-with-snacks event at the Brenden Theaters Concord 14 just one week later, he shared his story of the grueling climb with about 100 invited climbers and Contra Costa County Search and Rescue personnel.

“I’m totally knackered,” Florine said, describing his post-climb condition. Behind him, a selfie filled the enormous screen that, if placed on El Cap, would represent an area smaller than a postage stamp. “I’ve been lying there for 40 minutes, trying to get up energy to pack my gear.”

To understand the significance of the climb and why a man marking a half-century might be thrilled to lie atop a mountain with bits of cheese strewn across his chest, it’s important to know that the valley is teeming with arguably similar, nutty-speed climbing athletes — and has been for decades.

Before 1956, no one even thought the Valley’s comparatively “lower” 2,000-foot Half Dome could be climbed. Those who tried stored their water in tin cans or huge rubber bladders similar to those that soldiers once used on battlefields to hold their urine.

They wore cotton pants and 45-pound gear packs. Half Dome, roughly two-and-a-half times the height of San Francisco’s Trans America building, Florine said, had those early climbers only managing to cover a few hundred feet after five-day attempts.

One team, climbing 33 days spread out over 18 months, found themselves stuck and only two-thirds of the way up.

Eventually, a three-man team managed the feat in 1957.

Instantly — and an indication of things to come — American climber Warren Harding, who had been unsuccessful on Half Dome, upped the ante.

On Nov. 1, 1958, Harding and his team topped off El Capitan’s more formidable facade.

Like a cork exiting a champagne bottle, the race was on, as competitive climbers racked up reduced times in subsequent years.

By 2000, Florine said, showing a photo taken at a reunion in Yosemite, the sport could boast 600 endurance athletes who’d climbed in the valley throughout the decades.

And from the first ascents, as the number of participants boomed, clothing, gear, team size and the time between record-smashing speed climbs all got progressively smaller.

Florine’s own times also shrank, beginning with a whimper in 1988 as a college kid with a headlamp who took 13 hours and only reached The Face’s sickle ledge, he’d cut it to 16 minutes for the same distance by 2003.

Having won and lost the El Cap record more than a half dozen times, Florine holds the world record for climbing “The Nose” route in 2:23:46, set on June 17, 2012, with Alex Honnold.